DESCRIPTION: (Applicant's Abstract) The purpose of the proposed research is to develop and refine a new animal model for the affective and/or motivational states that are elicited by drugs of abuse. Ultimately, the purpose is to identify behavioral measures that predict drug-taking behavior. Critical features of drug-taking and relapse are the positive (i.e., reinforcing) effects of drugs and the aversive state associated with cessation of chronic drug-taking and withdrawal. Nonhuman primates, including baboons, emit a variety of distinct vocalizations during aversive (e.g., social separation, predator alarm, and agonistic interactions) and positive (e.g., feeding, grooming and copulation) social contexts. Vocalizations during these averse or positive social situations appear to serve different social functions and may serve as indications of affective and/or motivational states such as "anxiety" or "contentment". The social and affective nature of vocalizations render them particularly attractive for research on the subjective training with an artificial apparatus. Moreover, vocalizations are altered by positive an aversive environmental stimuli, and are modified when psychoactive drugs are administered. The current research will focus on psychoactive compounds that are abused in humans and that previously have been shown to be self-administered. The current research will focus on psychoactive drugs are administered. The current research will focus on psychoactive compounds that are abused in humans and that previously have been shown to be self -administered in baboon. These will include drugs from various drug classes including psychomotor stimulants, opiods, and sedatives. In the first series of experiments, acute doses of drugs will be administered to baboons and their effects on the production and patterning of vocal and visual display behaviors will be recorded during observation sessions before, during and after drug administration. The relationship between visual displays (including social behaviors, agonistic behaviors, self-directed behaviors, motor activity and resting postures) and the type of species-specific vocalizations (i.e., "grunts" and "barks") will be characterized under different social context conditions. In addition, some drugs that are not self-administered by baboons will be tested in order to determine the specificity of drug effects on vocalizations. In the second series of experiments, selected drugs will be administered chronically to determine whether repeated drug exposure and/or physical dependence alters vocalizations over time. The development of an animal model for the affective and/or motivational states that are elicited by drugs of abuse will provide a basis for future research on the role of the subjective effects of drugs in the addictive process.